Constrained random points on a circle: Difference between revisions
Constrained random points on a circle (view source)
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, 5 years ago→{{header|Perl 6}}: added sample output
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my %matrix;
for @range X @range -> ($x, $y) { %matrix{$y}{$x} = ' ' }
%matrix{
%matrix{$_}{@range}.join(' ').say for @range;</lang>
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Turning that program completely inside-out and reducing to a single statement with a single non-parameter variable, we get
This uses, among other things, a 0-based matrix rather than a hash, a <tt>given</tt> on the first line that allows us to print the final value of the matrix straight from its initial declaration, a <tt>for</tt> statement feeding a <tt>for</tt> statement modifier, a lambda that unpacks a single x-y argument into two variables, the functional form of pick rather than the method form, a quasi-list comprehension in the middle loop that filters each <tt>given</tt> with a <tt>when</tt>, precalculated squared limits so we don't have to take the square root, use of X- and X** to subtract and exponentiate both <tt>$x</tt> and <tt>$y</tt> in parallel.▼
▲Turning that program completely inside-out and reducing to a single statement with a single non-parameter variable, we get this version, which also works:
After the <tt>given do</tt> has loaded up <tt>@matrix</tt> with our circle, the <tt>map</tt> on the first line substitutes a space for any undefined matrix element, and the extra space between elements is supplied by the stringification of the list value, performed by the prefix <tt>~</tt> operator, the unary equivalent of concatenation in Perl 6.▼
At this point you would be justified in concluding that we are completely mad. <tt>:-)</tt>▼
<lang perl6>(say ~.map: { $_ // ' ' } for my @matrix) given do
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}
</lang>
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▲This uses, among other things, a 0-based matrix rather than a hash, a <tt>given</tt> on the first line that allows us to print the final value of the matrix straight from its initial declaration, a <tt>for</tt> statement feeding a <tt>for</tt> statement modifier, a lambda that unpacks a single x-y argument into two variables, the functional form of pick rather than the method form, a quasi-list comprehension in the middle loop that filters each <tt>given</tt> with a <tt>when</tt>, precalculated squared limits so we don't have to take the square root, use of X- and X** to subtract and exponentiate both <tt>$x</tt> and <tt>$y</tt> in parallel.
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▲After the <tt>given do</tt> has loaded up <tt>@matrix</tt> with our circle, the <tt>map</tt> on the first line substitutes a space for any undefined matrix element, and the extra space between elements is supplied by the stringification of the list value, performed by the prefix <tt>~</tt> operator, the unary equivalent of concatenation in Perl 6.
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▲At this point you would be justified in concluding that we are completely mad. <tt>:-)</tt>
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=={{header|Phix}}==
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